DVD Dual media - +RW media

There are now any number of dual layer DVD writers capable of writing to i.e. +RW - all those listed in the September DVD writers feature can wite to this media, but where, if anywhere can you get the media to go with it? Sure, there's losts of DL +R, but no +RW.

Ah ha. Thought so. So how do the manufacturers know that they wiull work with them when they do come out? Just being a little contentious, but, for the time being, I think I'll stand on the sidelines and await developments.